The repeated outbreaks of public health security incidents in recent years have raised people's attention to the field of public health security. The outbreak of public health security incidents will inevitably have a certain impact on public health fiscal expenditures. However, there is still no definite answer about the specific impact of the impact on public fiscal health expenditures. This paper first takes the SARS outbreak as the impact of an exogenous event, and adopts the TREAT×POST research method commonly used in academia to explore the impact of the SARS outbreak on public financial health expenditure. Expenditures have increased. This article speculates that fiscal health expenditures may have received attention in the government's expenditure structure. In order to protect the safety of people's lives, the government has used more fiscal expenditures to fight the epidemic.